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Multiple mesophases, including the smectic A phase (Sm A), chiral nematic phase (N*), and blue phase (BP I), were seen in a series of non-symmetric bent mesogenic dimers containing a cholesteryl benzoate group.

Iridium-containing liquid-crystalline polymers were obtained by graft copolymerisation using poly(methylhydrogeno)siloxane, 1-methyl-4-(4-(4-vinylcyclohexyl)cyclohexyl)benzene (M1) and an iridium c...

As the properties of materials can be determined by their structures, a novel liquid crystalline oligomer (LCO) was first designed and prepared. The LCO possessed reactivity with reduced graphene oxide (RGO) and could be used to modify RGO. Maleimide groups could be grafted onto the RGO surface via the Diels-Alder reaction, whereby the mesogenic units enable the LCO to have optical rotation and excellent liquid crystalline properties, while the carboxyl groups could improve the dispersibility of RGO in solvents and disperse more TiO2 on the surface of modified RGO than on pure RGO. Spectroscopic tools (Raman and XRD) were used to confirm the completion of the reaction. A Fourier transform infrared imaging was utilized to analyze the dispersibility of RGO in the RGO-LCO composites. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to determine the thermal properties of the composites. Due to the excellent thermal property of RGO and the interactions between RGO and LCO, the dispersed RGO can increase the decomposition activation energy and the glass transition of composites. RGO can enhance the photocatalytic degradation of TiO2 due to its high electron mobility and large specific surface area. By preventing the aggregation of TiO2 and RGO, thus improving the solubility and dispersion stability of the RGO and increasing the affinity of RGO to TiO2, the LCO-modified RGO was better than pure RGO to enhance the photocatalytic degradation efficiency of TiO2.

Epoxy/clay nanocomposites with a high degree of exfoliation were achieved by intercalating liquid crystalline epoxy into clay intragallery as well as using a so-called ‘solution compounding’ process. In this process, clay modified was first treated with trichloromethane to form organoclay-trichloromethane suspension followed by liquid crystalline epoxy modification. The liquid crystalline epoxy grafted clay was then mixed extensively with epoxy to form epoxy/nanoclay composites. The mechanism of exfoliation was explored by monitoring the change of morphology of organoclay during each stage of processing with X-ray diffraction (XRD). The liquid crystalline epoxy grafted clay synthesised was characterised by fourier transform infrared spectroscopy (FT-IR) and polarising optical microscopy (POM). The clay platelets uniformly dispersed and highly exfoliated in the whole epoxy matrix were observed using transmission electron microscopy (TEM) and FT-IR imaging system. The epoxy nanocomposites were fabricated by incorporating different liquid crystalline epoxy grafted clay loading. The results revealed that the incorporation of liquid crystalline epoxy grafted clay resulted in a significant improvement in glass transition temperature (Tg) derived from dynamic mechanical analysis (DMA) and thermal stability measured by thermogravimetric analysis (TGA).

Novel nematic fluorescent main-chain liquid crystalline ionomers containing Eu(III) ions (Eu-LCI) were synthesised by the use of bis(4-(chlorocarbonyl)phenyl) decanedioate (BD), 4,4-dihydroxybiphenyl (D), 2,5-dihydroxybenzoic acid (B) and anhydrous europium chloride. The chemical structures, liquid crystalline behaviours and fluorescence properties of Eu-LCI were characterised by various experimental techniques. The introduction of small amounts of europium ions endowed the LCI with excellent luminescence properties. POM results showed that europium ions did not change the liquid crystalline texture of the LCI. Fourier transform infrared imaging showed that europium ions were evenly distributed in the matrices of ionomers. A schematic diagram of nematic fluorescent LCI was established to demonstrate the interaction and distribution of the components. Eu-LCI showed reversible mesomorphic phase transitions, wide mesophase temperature ranges and high thermal stability. The thermogravimetric analysis (TGA) results showed that decomposition temperatures (5% weight loss) were greater than 308°C in all Eu-LCI. Eu-LCI can emit red light when excited. The luminescence intensity of Eu-LCI gradually increased with increase in Eu(III) ions from 0.3 to 1.5 mol%. The temperature dependence of luminescent intensity was studied in the liquid crystalline phase, where the fluorescence intensity of Eu-LCI decreased monotonically with increase in temperature.

A novel liquid crystalline epoxy resin based on the imine group was synthesised and structurally characterised by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The mesogenic behaviour of the monomer was measured by differential scanning calorimetry (DSC) and polarised optical microscopy (POM), and presented various textures in the extensive temperature range. Methyl nadic anhydride (MNA) was employed to cure the liquid crystalline epoxy resin and the curing process was investigated using POM and wide-angle X-ray diffraction (WAXD). Information about distribution of liquid crystalline epoxy resin in the blending system resulted from the FT-IR Imaging System, indicating that molecules of liquid crystalline epoxy resin can agglomerate to form anisotropic domains. The improvement in mechanical properties of diglycidyl ether of biphenol A (DGEBA) modified with liquid crystalline epoxy was achieved. Scanning electronic microscopy (SEM) showed that an extremely rough and highly deforme...

A novel series of siloxane-based chiral smectic side-chain liquid crystalline elastomers containing nematic and chiral mesogens were fabricated through synthesis involving a one-step hydrosilication reaction via a crosslinking agent containing smectic and nematic phases. The chemical properties and structures of the nematic mesogen (M1), the chiral mesogen (M2) and the LC crosslinking agent (CL) were carefully investigated by different analytical methods. All of the obtained side-chain liquid crystalline elastomers showed a chiral smectic phase from texture observations of POM which was confirmed by XRD analysis. The influence of CL on the phase behaviour of the chiral smectic side-chain liquid crystalline elastomers has been studied. The DSC analytical results showed that the glass transition temperatures (Tg) of the obtained elastomers increased with the gradual increase of the content of CL; while the isotropization temperatures (Ti) exhibited no remarkable changes. The thermal gravity analysis (TGA) revealed that the 5% weight loss of the decomposition temperature (Td) was greater than 280 °C for all the obtained elastomers, meaning the thermal stability of the elastomers was good. The fourier transform infrared (FT-IR) imaging system showed that the molecular distribution of the elastomers was relatively even. The effective crosslinking density of the elastomers was characterized by swelling experiments showing that the molecular weight between the crosslinking points decreases with an increase of the CL.

High adhesion hydrophobic surfaces with high apparent contact angles were achieved by a convenient approach. The morphology of the high adhesion surface both at the micrometre scale and at the nanometre scale can be changed by variation in the amount of carboxyl functionalized multi-wall carbon nanotubes. The contact angle values for the as-prepared surfaces are different, increasing from about 122.8° to 151.4° by increasing the amount of MWCNT–COOH. The as-prepared surface with a tunable adhesion can be achieved and the maximum volume of the water droplet adhered on the surface can be adjusted from about 5 μL to 35 μL. The variation in the contact angle and the maximum volume of the water droplet adhered on the surface are both attributed to the different morphologies of the surfaces. To analyze the correlation between the surface morphology and water droplet wetting, we suggest that the wetting state of the water droplet on the surface is changed, which results from the appearance of the micro/nano scale structure. Furthermore, a process of water droplet no-loss transport was achieved by the difference in adhesion of the surface.

Novel luminescent chiral network liquid-crystalline polymers containing Sm(III) ions (Sm-LCPs) exhibiting wonderful liquid crystalline properties and unique fluorescence properties were prepared by poly(methylhydrogeno)siloxane (PMHS), chiral liquid crystal monomer M1, crosslinking agent M2 and samarium complex M3. The chemical structures, liquid-crystalline behaviours of Sm-LCPs were characterized by various experimental techniques. The introduction of small amount of samarium ions endowed liquid-crystalline polymers with fascinating fluorescence properties. All Sm-LCPs were chiral, and samarium ions did not marked affect the textures of liquid-crystalline polymers. Fourier transform infrared imaging study exhibited that samarium ions were evenly distributed in polymers. A spiral structural model was established to demonstrate the distribution and interaction of components. All Sm-LCPs showed wide mesophase temperature ranges, reversible mesomorphic phase transitions and high thermal stability. The thermogravimetric analysis (TGA) results displayed that the decomposition temperatures (5% weight loss) of all Sm-LCPs were greater than 297 °C. The Sm-LCPs can emit soft red light when excited. Fluorescence intensity of Sm-LCPs gradually increased with increase in samarium complexes from 0.2 to 1.0 mol%. The temperature dependence of luminescence intensity was studied, where the fluorescence intensity of Sm-LCPs decreased monotonically with increase in temperature.

In order to effectively disperse reduced graphene oxide (RGO) in functional materials and take full advantage of its exceptional physical and chemical properties, a novel and effective approach for non-covalent modification of RGO by a chiral liquid crystalline surfactant (CLCS) consisting of chiral mesogenic units, nematic mesogenic units with carboxyl groups and non-mesogenic units with a polycyclic conjugated structure is firstly established. The polycyclic conjugated structure can anchor onto the RGO surface via π-π interactions, the chiral mesogenic units possess affinity for chiral materials by joining the helical matrix of chiral material and the carboxyl groups in nematic mesogenic units are supposed to form coordination bonds with nano zinc oxide (ZnO) to fabricate functional nano hybrids. The transmittances of CLCS-RGO hybrids exhibit S-shaped nonlinear increase with the increase of wavelength, but the total transmittances from 220 nm to 800 nm show a linear decreasing trend with the increase of RGO content in the CLCS-RGO hybrid. Due to the superior thermal properties of RGO and the interactions between RGO and CLCS, the dispersed RGO can improve the glass transition and increase the thermal stability and decomposition activation energy of CLCS. The intercalation of RGO can decrease the thermochromism temperature and improve the pitch uniformity of CLCS. Furthermore, CLCS can promote the dispersion of RGO in chiral nematic liquid crystals (CNLCs), and the CNLC-RGO-CLCS hybrids present decreased driving voltage and accelerated electro-optical response. The CLCS non-covalently modified RGO can strengthen the photocatalytic degradation of ZnO by suppressing the aggregation of ZnO and RGO.

A effective way for covalent modification of reduced graphene oxide (RGO) by a chiral side-chain liquid crystalline oligomer (CSLCO) is firstly established. CSLCO consists chiral mesogenic units, non-mesogenic units with carboxyl groups and nematic mesogenic units with conjugated diene structure, the properties of materials should be determined by their structures. The conjugated diene structure can be grafted onto the RGO surface via Diels–Alder (DA) reaction, the chiral mesogenic units would enable CSLCO to have optical rotation and the carboxyl groups are expected to constitute coordination bonds with nano titanium oxide (TiO2) to fabricate composites. Spectroscopic tools (Raman and XRD) are used to confirm the completion of the DA reaction. Fourier transform infrared imaging system is utilized to analyze the dispersibility of RGO in the RGO–CSLCO composites. Due to the excellent thermal property of RGO and the interactions between RGO and CSLCO, the dispersed RGO can increase the glass transition and the decomposition activation energy of CSLCO. RGO can enhance the photocatalytic degradation of TiO2 due to its high electron mobility and large specific surface area. By preventing the aggregation of TiO2 and RGO, the CSLCO covalently modified RGO is better than pure RGO to enhance the photocatalytic degradation efficiency of TiO2.

Fluorescent chiral fluorinated liquid crystalline polymers containing rare earth complexes (RE-LCPs) possessing wonderful liquid crystalline properties and distinct fluorescence properties were graft copolymerized using poly(methylhydrogeno)siloxane (PMHS), a chiral fluorinated liquid crystalline monomer (M1), and a fluorinated rare earth complex (RE-M2). The chemical structures and liquid crystalline behaviors of RE-LCPs were characterized using various experimental techniques. The introduction of a low amount of fluorinated rare earth complexes endowed the polymers with momentous luminescence properties. All the polymers were chiral. The rare earth complexes did not change the liquid crystalline textures of the polymers which were confirmed by X-ray diffraction. Fourier transform infrared imaging exhibited that the rare earth complexes were evenly distributed in polymers. A structural model of RE-LCPs was established to express the interaction and the distribution of the components. The RE-LCPs displayed reversible mesomorphic phase transitions, wide mesophase temperature ranges, and high thermal stabilities. The thermogravimetric analysis (TGA) results showed that the decomposition temperatures (5% weight loss) of RE-LCPs were greater than 300 °C in all RE-LCPs. The RE-LCPs can emit soft red light or green light when being excited. Luminescence intensities of the RE-LCPs gradually increased with an increase of rare earth complexes from 0 to 1.5 mol%. The temperature dependence of fluorescence intensity was studied in a liquid crystalline phase, where the fluorescence intensities of RE-LCPs decreased monotonically with the increase of temperature.

In some cold areas/regions, ice accumulation is harmful to aircrafts, highways and power lines. To overcome this challenge, many researchers have focused on developing anti-icing surfaces. In this paper, liquid crystal compound Cholest-5-en-3-ol(3β)-4-(2-propenyloxy)benzoate was synthesised, and a liquid crystal surface (LC surface) is prepared by heating the liquid crystal compound to 250°C and then cooling it. We determined ice-phobic properties of LC surface using differential scanning calorimetry (DSC) and polarised optical microscope (POM). A phenomenon that the freezing of water droplet on the LC surface is delayed was found. Compared with the two measurement methods, we obtained similar result that water freezing temperature was delayed nearly by 8°C on average on the LC surface. A process of ice/frost formation is observed using POM. The results displayed that the glass wafer without LC was covered completely by ice/frost, whereas on the LC surface at the same temperature no ice/frost was formed. Characteristics of LC surface were observed by field emission scanning electron microscope (FESEM) and Fourier transform infrared (FT-IR) imaging system. We suggest that the reason behind anti-ice surface is related to surface molecules and this is an important factor which may have an effect on anti-icing property.

An effective and promising approach for dispersion and alignment of carbon nanotubes (CNTs) with the help of fluorinated liquid crystalline surfactants (FLCSs), which possess excellent affinity with CNTs and liquid crystals (LCs), is presented here. A binary mode is designed to express the dispersion of CNTs with CNTs joining the nematic matrix of FLCSs. Ultraviolet–visible spectrum and fourier transform infrared (FTIR) spectrum are recorded to figure out the concentration of effectively dispersed CNTs by FLCSs, the concentration in chloroform reaches a maximum 1.481 mg mL−1. The miscibility between FLCSs and CNTs is analyzed by FTIR imaging system with P7 giving rise to the best miscibility. The homogeneously dispersed CNTs decrease the glass transition temperature of FLCSs by increasing the degree of freedom of the segment on FLCS to move, and enhance the thermal stability of FLCSs by increasing the decomposition temperature and the activation energy for thermal decomposition. The optical textures show that P7 increases the compatibility between LC host and CNTs. The chiral stability and electro-optical property of LC host are both optimized by CNT doping.

Novel photoluminescent chiral liquid crystalline oligomers with lanthanide ions (Ln-LCOs) exhibiting excellent liquid crystalline properties and unique fluorescence properties were prepared using poly(methylhydrogeno)siloxane, cholesteric LC M1, carboxyl-containing LC M2 and anhydrous lanthanide chlorides. The chemical structures and liquid-crystalline behaviors of Ln-LCOs were characterized by various experimental techniques. The introduction of low content of lanthanide ions endowed the oligomers with significant luminescence properties. All the oligomers were chiral. The lanthanide ions did not change the liquid crystalline textures of the oligomers which were confirmed by X-ray diffraction. Fourier transform infrared imaging study indicated that the lanthanide ions were evenly distributed in the oligomers, which avoided the fluorescence quenching caused by the aggregation of lanthanide ions. A binary complex model with lanthanide ions acting as central ions and chiral liquid crystalline oligomers acting as ligands was established to express the interaction and distribution of the components. The Ln-LCOs showed reversible mesomorphic phase transitions, wide mesophase temperature ranges, and high thermal stabilities. The thermogravimetric analysis results displayed that the decomposition temperatures (5% weight loss) of all Ln-LCOs were greater than 300 °C. The Ln-LCOs can emit red light or green light when being excited. Luminescence intensities of the Ln-LCOs gradually increased with an increase of lanthanide ions from 1 to 4 mol%. The temperature dependence of luminescent intensity was studied, where the fluorescence intensities of Ln-LCOs decreased monotonically with an increase of temperature in liquid crystalline phases.

A novel and effective way to disperse carbon nanotubes (CNTs) by using amphiphilic chiral side-chain liquid crystalline oligomers (ACSLCOs) as chiral surfactants, which possess dual affinity for both CNTs and chiral liquid crystals (CLCs), is reported here for the first time. For the binary system consisting of CNTs and ACSLCOs, the concentration of CNTs dispersed by ACSLCOs was determined by Fourier transform infrared (FTIR) spectroscopy combined with ultraviolet-visible-near infrared spectroscopy. The ability to disperse CNTs increases as the mole fraction of polycyclic conjugated structures on the chiral surfactants increases, and the concentration reaches 0.85 mg mL−1. The dispersion state of the CNTs in the composites was characterized by a FTIR imaging system, and the CNT–O7 composite demonstrated the best dispersion of CNTs. The evenly dispersed CNTs reduce the glass transition temperature and improve the thermal stability of the ACSLCOs. For the ternary system consisting of CNTs, O7 and a low molecular weight CLC, the dispersion state of the CNTs was characterized using a polarized optical microscope. The results show that the CNTs possess excellent compatibility with the low molecular weight CLCs with the assistance of O7. The dispersed CNTs are proven to have increased the chiral stability of the chiral host by the measurement of the Bragg selective reflection.

In recent years, modified liquid crystal (LC) material has been widely applied in display industry for outstanding performances by changing the prescription or adding additives. Polymer stabilised cholesteric liquid crystal (PSCLC) was designed with the aim for achieving better performance. In this study, a stable system was established by doping FexNiy nanoparticles into a PSCLC film, in which nanoparticles (NPs) were modified by organic LC molecules. The NPs composite were monodispersed evenly in PSCLC film without agglomeration. The electrical-optical performance was improved in different ways. The minimum reported response time of FeNi, FeNi3 and Ni was 3.32, 3.45 and 4.32 ms, which showed 72.33%, 71.25% and 64% reduction, respectively. However, the drive voltage of FeNi, FeNi3 and Ni was 6.92, 6.58 and 6.84 V which showed 61.56%, 63.44% and 62% reduction, respectively. The viewing angle of PSCLC was extended. Besides, as the drive frequency was raised by 5 kHz, Vth dropped from 6.58 to 1.62 V, and de...

Luminescent liquid crystalline polymers consisting of Iridium attached to polysiloxanes are prepared. 4-Cyanophenyl 4-(allyloxy) benzoate (M1) and an Iridium complex (Ir-M2) grafted to poly(methylhydrogeno)siloxane are used for the preparation of the Iridium-containing liquid crystalline polymers. The chemical structures are characterised by Fourier transform infrared spectroscopy and 1H NMR. The mesomorphic properties and phase behaviour are investigated by differential scanning calorimetry, thermogravimetric analysis, polarising optical microscopy and X-ray diffraction. The polymers containing

Cholesteric liquid crystal (CLC) with helically aligned molecules, demonstrates unique optical features. Conventionally, such structure reflects a maximum 50% of unpolarised light. Polymer-stabilised CLC was designed to exceed the limit by mixing liquid crystal (LC) and a photopolymerisable monomer of opposite chirality. The reflectance was carefully investigated and the result was 55.7% in the visible region at room temperature, where it exceeded the theoretical limit. Such phenomena were studied and theoretical model was discussed. Electro-optical test showed the driving voltage was of LC cell was slightly changed after polymerisation.

A liquid crystalline compound containing (−)-menthol as a chiral centre was prepared and used as a host material, the liquid crystalline behaviour of which were investigated. The host did not exhibit any blue phases on heating and cooling. A series of conventional rod-shaped hydrogen-bonded supermolecules with different terminal chain lengths were synthesized and used as dopants. These supermolecules did not possess chirality or exhibit any mesomorphic behaviour. By adding proton acceptors, proton donors and supermolecules into the host liquid crystal, respectively, the effects of these dopants on the liquid crystalline properties of the mixtures were studied. The formation of blue phases was induced by adding supermolecules into the host liquid crystals. The widest temperature range of the blue phase was about 45 K.

Two series of novel composite nanofiltration (NF) membranes were prepared by the overcoating of polysulfone ultrafiltration membranes with a mixture of chitosan and chitosan derivatives modified with two different chiral compounds. The two chiral compounds and their chitosan derivatives were characterized by IR spectroscopy, differential scanning calorimetry, and polarimetry. The structure of the membrane was characterized by scanning electron microscopy (SEM). The rejection and flux of the composite NF membranes were strictly related to the chiral compound grafted to chitosan and its composition in the mixture. An extremely high rejection, 98.23%, was observed with P2–3 of the polymer (P2) composite NF membrane, and the flux remained as high as 351 L m−2 h−1 at 0.4 MPa with 1000 mg/L NaCl. These results, together with SEM and IR images of the composite NF membrane, indicated that the chiral compound structure was crucial for the structure and function of the composite membrane. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Conventional nanofiltration (NF) membranes had a relatively low flux. In this paper, two mesogenic compounds were grafted to chitosan in order to change the structure, hence the performance of the NF membrane. A series of novel composite NF membranes were prepared by over-coating the polysulfone ultrafiltration membrane with the mixture of chitosan and mesogenic compounds modified chitosan. The two mesogenic compounds and their chitosan derivatives were characterized by infrared spectrophotometer (IR), differential scanning calorimetry (DSC), polarized optical microscope (POM); the structure of the membrane was characterized by scanning electron microscopy (SEM). The composite NF membrane's rejection rate and flux were strictly related to the mesogenic compound grafted to chitosan and its composition. Extremely high flux, 2543.3 lm − 2 h − 1 was observed with P 2–4 composite NF membrane, and the rejection remained to be as high as 66.3% at 0.4 MPa with 1000 mg/L NaCl. These results, together with SEM and infrared images of the composite NF membrane, indicated that the mesogenic compound structure was crucial for the structure and function of the composite membrane.

Three esters of maltose (A1–A3) with 4–(4–(alkoxybenzoyloxy)phenoxy) –6–oxohexanoic acid (b1–b3) side-arms have been synthesised. All the maltose derivatives were laevo-rotationary, unlike their parent cores. The side arm b1 did not display liquid crystalline (LC) properties, and b2 and b3 displayed thermotropic nematic LC properties. The star-shaped compound (SSC) A1 with b1 side-arms did not display a mesomorphic phase. Unlike the nematic schlieren texture provided by side-arms b2 and b3, the star-shaped liquid crystals (SSLC) A2 and A3 displayed Grandjean and oily texture in the cholesteric phase. The results suggest that the LC properties of the side-arms have an important influence on the formation of LC properties in an SSC, and that the maltose core is important in determining the mesomorphic phase type. In other words, the SSC displayed LC properties only when the side-arms were also LC, and the maltose core induced a cholesteric phase in the SSLC with nematic side-arms. The mesomorphic regions fo...

A series of novel star‐shaped carbohydrate derivative liquid crystals was synthesized with glucose as the chiral core structure. Glutamyl mesogenic moieties, l‐R‐{n‐[4‐(cholesteryloxycarbonyl)benzoyloxy]alkoxy}glutamic acid, were introduced to the five hydroxy groups of glucose by direct esterification. The chemical structures of the target liquid crystalline compounds were confirmed by element analysis and Fourier transform infrared, 1H NMR and 13C NMR spectroscopy. The mesomorphic behaviour and thermal properties of target liquid crystalline compounds were investigated with differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, X‐ray diffraction and specific rotation. All the target compounds exhibit a cholesteric liquid crystalline phase. These compounds demonstrate a wide mesogenic region and high thermal stability. The effect of flexible spacer group length of the target compounds on the molecular structure and thermal properties is discussed.

A series of new side-chain liquid crystalline polymers containing chenodiol residue derived from 24-[4′-hydroxybiphenyl-4-yl-4-(allyloxy)benzoyloxy]-3α,7α-di{n-[4′-(4-ethoxybenzoyloxy)biphenyl-4-yloxy]-n-oxoalkanoyloxy}-5β-cholane was designed and prepared. The chemical structures of the monomer and polymer were confirmed by Fourier transform infrared and 1H NMR spectra. The mesomorphic properties of monomer and polymer were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction. The side-chain liquid crystalline polymers revealed wide mesophase temperature range and high thermal stability, and they showed nematic liquid crystalline phase. The influence of flexible space group length on thermal properties and specific rotation was examined.

Chiral network surfactants (CNSs) possessing miscibility with carbon nanotubes (CNTs) and chiral materials are applied to disperse CNTs. Ultraviolet-visible absorption spectroscopy is used to quantitatively determine the CNT concentration in homogeneous CNT-CNS dispersions, results indicate that CNSs with more mole fraction of polycyclic conjugated structure have better ability to load and disperse CNTs and the maximal concentration reaches 0.79 mg mL(-1). Fourier transform infrared imaging system is utilized to analyze the dispersibility of CNTs in CNT-CNS composites, and CNS with 6 mol % nonmesogens (S6) induces the best dispersibility. The CNT doped CNSs exhibit lower glass transition temperature, strengthened thermal stability, decreased the thermochromic temperature and enriched reflected colors of CNSs. Furthermore, S6 are used as a promoter to disperse CNTs in chiral host, here, a left-handed chiral liquid crystal (CLC) is selected, the miscibility between CNTs and CLCs is studied by polarized optical microscope, and CNTs can be effectively dispersed in CLCs by S6. The CNT dispersed CLCs can exhibit a faster electro-optical response process than neat CLCs.

Luminescent cholesteric liquid crystalline polymers consisting of the lanthanide ions covalently attached to cholesteric polysiloxanes are prepared. Cholesteric liquid crystalline monomer and 4-(allyloxy)benzoic acid grafted to poly(methylhydrogeno)siloxane is used as one of the precursors for the preparation of the lanthanide-containing cholesteric liquid crystalline polymers. The chemical structures of the monomers are characterised by Fourier transform infrared, 1H NMR and elemental analyses. The mesomorphic properties and phase behaviour are investigated by differential scanning calorimetry, thermogravimetric analysis, polarising optical microscopy and X-ray diffraction. The polymers containing

Many clinically used protein therapeutics are modified to increase their efficacy. Example modifications include the conjugation of cytotoxic drugs to monoclonal antibodies or poly(ethylene glycol) (PEG) to proteins and peptides. Monothiol-specific conjugation can be efficient and is often accomplished using maleimide-based reagents. However, maleimide derived conjugates are known to be susceptible to exchange reactions with endogenous proteins. To address this limitation in stability, we have developed PEG-mono-sulfone 3, which is a latently reactive, monothiol selective conjugation reagent. Comparative reactions with PEG-maleimide and other common thiol-selective PEGylation reagents including vinyl sulfone, acrylate, and halo-acetamides show that PEG-mono-sulfone 3 undergoes more efficient conjugation under mild reaction conditions. Due to the latent reactivity of PEG-mono-sulfone 3, its reactivity can be tailored and, once conjugated, the electron-withdrawing ketone is easily reduced under mild conditions to prevent undesirable deconjugation and exchange reactions from occurring. We describe a comparative stability study demonstrating a PEG-maleimide conjugate to be more labile to deconjugation than the corresponding conjugate obtained using PEG-mono-sulfone 3.

Luminescent lanthanide-containing chiral liquid crystalline polymers are graft-copolymerised using poly(methylhydrogeno)siloxane (PMHS), crosslinking agent, liquid crystalline monomer and lanthanide complexes. The chemical structures of the monomers are characterised by FTIR, 1 H NMR and elemental analyses. The mesomorphic properties and phase behaviour are investigated by differential scanning calorimetry, thermogravimetric analysis, polarising optical microscopy and X-ray diffraction. The polymers containing less than 9 mol% of the crosslinking units reveal reversible mesomorphic phase transition, wide mesophase temperature ranges and high thermal stability. With the introduction of lanthanide complex units, the polymers are enabled with the significant luminescent properties. The temperature dependence of fluorescence intensity was studied in the liquid crystalline phase. The IR imaging shows that the lanthanide complex units evenly distribute in polymers.

The efficacy of protein-based medicines can be compromised by their rapid clearance from the blood circulatory system. Achieving optimal pharmacokinetics is a key requirement for the successful development of safe protein-based medicines. Protein PEGylation is a clinically proven strategy to increase the circulation half-life of protein-based medicines. One limitation of PEGylation is that there are few strategies that achieve site-specific conjugation of PEG to the protein. Here, we describe the covalent conjugation of PEG site-specifically to a polyhistidine tag (His-tag) on a protein. His-tag site-specific PEGylation was achieved with a domain antibody (dAb) that had a 6-histidine His-tag on the C-terminus (dAb-His(6)) and interferon α-2a (IFN) that had an 8-histidine His-tag on the N-terminus (His(8)-IFN). The site of PEGylation at the His-tag for both dAb-His(6)-PEG and PEG-His(8)-IFN was confirmed by digestion, chromatographic, and mass-spectral studies. A methionine was also inserted directly after the N-terminal His-tag in IFN to give His(8)Met-IFN. Cyanogen bromide digestion studies of PEG-His(8)Met-IFN were also consistent with PEGylation at the His-tag. By using increased stoichiometries of the PEGylation reagent, it was possible to conjugate two separate PEG molecules to the His-tag of both the dAb and IFN proteins. Stability studies followed by in vitro evaluation confirmed that these PEGylated proteins retained their biological activity. In vivo PK studies showed that all of the His-tag PEGylated samples displayed extended circulation half-lives. Together, our results indicate that site-specific, covalent PEG conjugation at a His-tag can be achieved and biological activity maintained with therapeutically relevant proteins.

Site-specific PEGylation reagents have been developed that undergo thiol-specific bis-alkylation with the two cysteine sulphur atoms from a native accessible disulphide in proteins. The process for this approach of site-specific PEGylation involves two steps: (1) disulphide reduction to release the two thiols and (2) bis-alkylation of the PEG reagent to the two sulphur atoms to give a three-carbon bridge to which PEG is covalently attached. Mechanistically, the conjugation is thought to occur by a sequential, interactive bis-alkylation that requires functionalised PEG reagents that have a α, β-unsaturated β′-mono-sulphone moiety. Competitive reactions can be effectively suppressed to achieve high yield PEGylation with a stoichiometric equivalence of the reagent. The reagents are easily prepared and precursor forms of our PEG reagents can be used to control the rate of formation of the reactive PEG mono-sulphone in situ that undergoes conjugation with the protein. Purification is often a simple process where un PEGylated protein can be easily recycled to further increase yields. Many classes of therapeutically relevant proteins possess accessible native disulphides. Our studies have shown that peptides, proteins, enzymes and antibody fragments can be site-specifically PEGylated by bis-alkylation using a native, accessible disulphide.

Synthesis of carbohydrate-derived liquid crystals by assembling D-(+)-glucose with mesogenic units containing chenodiolyl moieties and a flexible spacer is reported for first time and the thermal p...